ABSTRACT
STUDY DESIGN: This is a retrospective case study. PURPOSE: This study was designed to analyze the surgical outcomes of patients who underwent minimally invasive transforaminal lumbar interbody fusion (TLIF) for the treatment of spondylolisthesis and degenerative segmental instability. OVERVIEW OF LITERATURE: If the surgical outcomes of a procedure are evaluated together with multiple indications, it is not clear how the procedure helped each subgroup of patients. For the reason that some indications achieve better outcomes than the others, we performed a subgroup analysis using validated outcome measures to demonstrate the optimal indications and the treatment results of TLIF. METHODS: We conducted subgroup analyses by comparing the prospectively collecting data from the consecutive patients who underwent single-level minimally invasive TLIF for the treatment of the following 3 subgroups of indications: 23 cases of low-grade spondylolytic spondylolisthesis, 24 cases of degenerative spondylolisthesis, and 19 cases of degenerative segmental instability. RESULTS: The average duration of follow up was 36.1 +/- 9.9 months (range, 24 to 63 months). The preoperative pain and disability scores were significantly improved at final postoperative follow-up in all the subgroups (all measurements: p < 0.0001). The 3 subgroups exhibited an equivalent improvement of the pain and disability scores at the final follow-up. The rates of radiographic solid fusion and complications were also similar among the 3 groups. CONCLUSIONS: Our data suggests that minimally invasive TLIF optimally and equivalently alleviates all of the associated symptoms and disabilities from low-grade spondylolisthesis and degenerative segmental instability. Furthermore, these patients seem to have optimal surgical indications for minimally invasive TLIF, while maintaining favorable surgical outcomes.